Oh no! Your car will still be drivable without the muffler, but I recommend parking your vehicle until it can be fixed or replaced.
Your car will also be emitting carbon monoxide and other gasses that will overwhelm your senses, and not in a good way. Your vehicle will get stinky—fast!
Lastly, driving without a muffler costs more money in the long run. The fuel efficiency will drop, and the chances of developing an exhaust or engine problem will rapidly increase. Have a local mechanic take a look, and hopefully, they can weld the muffler back on.